(1) Field of the Invention
The invention relates to a laminate, for example designed as a laminated panel, comprising at least one series of metal layers and plastic layers, which comprise fibers and are impregnated with a plastic material, attached to one another.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
A laminate of this type is known from WO-A-9853989 and is used, for example, in cladding panels for aircraft. In that case, the metal layers usually consist of an aluminum alloy. The plastic layers may, for example, be composed of plastic fibers with a high modulus of elasticity and consist, for example, of aramid. The plastic material with which the fibers are impregnated may be either a thermoplastic or a thermoset.
The advantage of a laminated panel is that the strength and rigidity properties can be locally adjusted. For example, at the locations where relatively high loads occur, for example around door openings, additional layers can be included in the laminate. In this way, by means of suitable selection of the dimensions of the layers, it is possible to obtain a gradual transition between the various regions in the panel without stress concentrations being otherwise introduced.
Panels of this type were joined to one another by means of a seam or splice, in which the edges or panels of this type overlap one another. An overlap of this type, which is disclosed by NL-C 1015141, however, forms a sudden, external interruption to the continuous nature of the aircraft cladding composed of panels of this type. WO-A-9853989 has also disclosed a connection between the various layers in the panels in which a separate connecting strip (doubler) is used. A connecting strip of this type also disturbs the externally continuous character of the panels. Interruptions of this type are undesirable both for reasons of aerodynamics and of strength and rigidity.
In addition, it is known to produce the laminate as a whole in various types, with more or fewer layers, in order to create panels which are intended for zones of an aircraft, for example, which are subjected to higher or lower levels of load. For example, there are panels with four metal layers, between each of which there are sets having two plastic layers (type Glare® 3). In yet another type, three metal layers are used in combination with sets of three plastic layers (Glare® 4).